Text optimization

Abstract

A method of providing text data for display in a processor controlled apparatus comprised of storing data defining a text character in a memory, in packed monochrome bit map form, addressing the memory to read the text character data, providing the text character to a graphics processor circuit, performing a bitblt operation on each bit of the text character while providing a color attribute, and storing the packed text character having a color attribute for subsequent display.

We claim:  
     
       1. A method of providing text data for display in a processor controlled apparatus comprising: 
       (a) storing data defining a text character in a memory, in packed monochrome bit map form,  
       (b) addressing the memory to read the text character data,  
       (c) providing the text character in packed form to a graphics processor circuit,  
       (d) performing a bitblt operation on each bit of the packed form of text character while providing a color attribute, and  
       (e) storing the packed text character having a color attribute for subsequent display.  
     
     
       2. A method of providing text data for display in a processor controlled apparatus as defined in  claim 1  further comprising: 
       (f) storing said data defining a text character in a graphics accelerator memory,  
       (g) performing the bit block transfer (bitblt) operation on the text character comprising reading source bit defining a block of text characters line by line in an X direction,  
       (h) defining a destination pointer for each block with X and Y coordinates,  
       (i) adding an offset to one of the X and Y coordinates, and  
       (j) writing the text character to a destination,  
       whereby each text character block is written to said destination, offset from a previous block by said added offset, for subsequent display in a predetermined order in said destination.  
     
     
       3. A method as defined in  claim 2  in which said offset is one of zero, in which the X and Y coordinates of the destination are not offset from a previous destination block position defined by a character pixel sequence; in which the X coordinate of the destination is positive and is offset to the right of a previous destination and the Y coordinate is zero and is not offset from a previous destination block position; in which the X coordinate of the destination is negative and is offset to the left of a previous destination and the Y coordinate is zero and is not offset from a previous destination block position; in which the X coordinate is zero and is not offset from a previous destination position and in which the Y coordinate is positive and is offset downward from a previous destination position; and in which the X coordinate is zero and is not offset from a previous destination position and the Y coordinate is negative and is offset upward from a previous destination position. 
     
     
       4. A method as defined in  claim 3  in which values of said positive and negative coordinate offsets are equal to a pixel length of a character block width and height respectively. 
     
     
       5. A method as defined in  claim 3  including storing by means of a program values of said offsets and using said values during the bitblt operation. 
     
     
       6. A method as defined in  claim 3  in which the coordinate offsets have values multiplied by −1. 
     
     
       7. A method of providing text data for display in a processor controlled apparatus comprising: 
       (a) storing data defining a text character in a memory,  
       (b) performing a bit block transfer (bitblt) operation on the text character by moving a source block of pixels of the text character from a source portion of the memory to a destination portion of the memory,  
       (c) the bitblt operation being performed by  
       (i) reading pixels in an X direction from the source block of pixels until the end of a destination block of pixels is reached while writing said pixels in an X direction to the destination portion of the memory,  
       (ii) advancing a destination block of pixels pointer in a Y direction which is orthogonal to the X direction and resetting the destination block to an X origin of said destination block of pixels, and  
       (iii) reading a next line of the source block of pixels in an X direction from the beginning of a next byte of the source block of pixels while skipping any bits in a preceding line of the source block of pixels remaining unread.  
     
     
       8. A method of providing text data for display in a processor controlled apparatus as defined in  claim 7 , in which the data defining a text character is stored in a graphics accelerator memory, and in which the bitblt operation includes the steps of: 
       (I) defining a destination pointer for each block with x and Y coordinates,  
       (II) adding an offset to one of the X and Y coordinates, and  
       (III) writing the text character to a destination,  
       whereby each text character block is written to said destination, offset from a previous block by said added offset, for subsequent display in a predetermined order in said destination.  
     
     
       9. A method as defined in  claim 8  in which said offset is one of zero, in which the X and Y coordinates of the destination are not offset from a previous destination block position defined by a character pixel sequence; in which the X coordinate of the destination is positive and is offset to the right of a previous destination and the Y coordinate is zero and is not offset from a previous destination block position; in which the X coordinate of the destination is negative and is offset to the left of a previous destination and the Y coordinate is zero and is not offset from a previous destination block position; in which the X coordinate is zero and is not offset from a previous destination position and in which the Y coordinate is positive and is offset downward from a previous destination position; and in which the X coordinate is zero and is not offset from a previous destination position and the Y coordinate is negative and is offset upward from a previous destination position. 
     
     
       10. A method as defined in  claim 9  in which values of said positive and negative coordinate offsets are equal to a pixel length of a character block width and height respectively. 
     
     
       11. A method as defined in  claim 9  including storing by means of a program, values of said offsets and using said values during the bitblt operation. 
     
     
       12. A method as defined in  claim 9  in which the coordinate offsets have values multiplied by −1.